Semiconductor device including a cutting region having a height greater than a height of a channel structure

ABSTRACT

A semiconductor device includes a peripheral circuit region on a lower substrate, and including circuit elements, memory cell regions including memory cells on each of a first upper substrate and a second upper substrate, which are on the lower substrate, at least one cutting region between the first upper substrate and the second upper substrate, and at least one semiconductor pattern between the first upper substrate and the second upper substrate, and adjacent to the at least one cutting region.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. application Ser. No.16/227,919, filed Dec. 20, 2018, issued as U.S. Pat. No. 11,133,267,which claims priority to Korean Patent Application No. 10-2018-0047766filed on Apr. 25, 2018, in the Korean Intellectual Property Office, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Field

The present inventive concept relates to a semiconductor device and amethod for manufacturing the same.

2. Description of Related Art

As demand for high performance, high speed, and/or versatility inelectronic devices increases, the degree of integration of semiconductordevices in electronic devices is also increasing. According to the trendfor higher degrees of integration of semiconductor devices, patterns forforming semiconductor devices are becoming smaller. Therefore, it may beimportant to reduce or prevent defects in a manufacturing process.

SUMMARY

An aspect of the present inventive concept is to provide a semiconductordevice with improved reliability and a method for manufacturing thesame.

According to an aspect of the present inventive concept, a semiconductordevice comprises: a peripheral circuit region on a lower substrate, andcomprising circuit elements; memory cell regions comprising memory cellson each of a first upper substrate and a second upper substrate, whichare on the lower substrate; at least one cutting region between thefirst upper substrate and the second upper substrate; and at least onesemiconductor pattern between the first upper substrate and the secondupper substrate, and adjacent to the at least one cutting region.

According to an aspect of the present inventive concept, a semiconductordevice comprises: a lower substrate; circuit elements on the lowersubstrate; a lower interlayer insulating layer at least partiallycovering the circuit elements; a plurality of upper substrates on thelower substrate; a plurality of gate electrodes on the plurality ofupper substrates, respectively; an upper interlayer insulating layer atleast partially covering the plurality of gate electrodes; and at leastone cutting region between the plurality of upper substrates, andpassing through the upper interlayer insulating layer and in contactwith the lower interlayer insulating layer.

According to an aspect of the present inventive concept, a method formanufacturing a semiconductor device comprises: forming circuit elementscomprising a peripheral circuit on a lower substrate; forming uppersubstrates and semiconductor patterns connecting the upper substrates toeach other; alternately stacking sacrificial layers and mold insulatinglayers on the upper substrates; forming channel structures passingthrough the sacrificial layers and the mold insulating layers; formingat least one cutting region between the semiconductor patterns; andremoving the sacrificial layers and forming gate electrodes in a regionfrom which the sacrificial layers are removed.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description, taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a schematic plan view of a semiconductor device according toan example embodiment of the inventive concept;

FIG. 2 is an enlarged view of region ‘A’ of FIG. 1 ;

FIG. 3 is a schematic cross-sectional view of a semiconductor deviceaccording to an example embodiment of the inventive concept, and across-sectional view taken along line I-I′ of FIG. 2 ;

FIG. 4 is a schematic plan view illustrating a portion of asemiconductor device according to an example embodiment of the inventiveconcept, and illustrates a region corresponding to FIG. 2 ;

FIG. 5 is a schematic cross-sectional view of a semiconductor deviceaccording to an example embodiment of the inventive concept;

FIG. 6 is a schematic plan view of a semiconductor device according toan example embodiment of the inventive concept;

FIG. 7 is an enlarged view of region ‘A’ of FIG. 6 ;

FIG. 8 is a schematic cross-sectional view of a semiconductor deviceaccording to an example embodiment of the inventive concept, and across-sectional view taken along line I-I′ of FIG. 7 ;

FIG. 9 is a schematic plan view illustrating a portion of asemiconductor device according to an example embodiment of the inventiveconcept, and illustrates a region corresponding to FIG. 7 ;

FIG. 10 is a schematic cross-sectional view of a semiconductor deviceaccording to an example embodiment of the inventive concept;

FIGS. 11 to 14 are schematic plan views illustrating a portion of asemiconductor device according to example embodiments of the inventiveconcept;

FIG. 15 is a schematic plan view illustrating a portion of asemiconductor device according to an example embodiment of the inventiveconcept;

FIG. 16 is a schematic cross-sectional view of a semiconductor deviceaccording to an example embodiment of the inventive concept, and across-sectional view taken along line I-I′ of FIG. 15 ; and

FIGS. 17 to 26 are schematic cross-sectional views illustrating a methodfor manufacturing a semiconductor device according to an exampleembodiment of the inventive concept.

DETAILED DESCRIPTION

Hereinafter, example embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items.

Some embodiments of the inventive concept stein from a realization thatin a Cell on Peripheral (COP) of a VNAND device, during an etchingprocess for formation of a channel hole, positive ions may accumulate onan upper substrate below the channel hole and electrons may accumulatein the Amorphous Carbon Layer (ACL) mask. As a result, a potentialdifference may be generated, which result in arcing. To prevent orreduce the likelihood of the arcing occurring, bridge patterns may beformed to connect upper substrates to each other and go ground an uppersubstrate to a lower substrate. Then, the channel holes are etched.After the etching of the channel holes is completed, the bridge patternsmay be cut using cutting areas defined therefor. Thus, the bridgepatterns may serve as a current path to discharge any potentialdifference that may be generated during the etching process, therebyreducing the risk of unwanted arcing.

FIG. 1 is a schematic cross-sectional view of a semiconductor deviceaccording to an example embodiment of the inventive concept. FIG. 2 isan enlarged view of region ‘A’ of FIG. 1 . FIG. 3 is a schematiccross-sectional view of a semiconductor device according to an exampleembodiment of the inventive concept, and a cross-sectional view takenalong line I-I′ of FIG. 2 .

Referring to FIGS. 1 to 3 , a semiconductor device 10 may include alower substrate 101 and upper substrates 201 disposed on the lowersubstrate 101. A peripheral circuit region PERI, which may be considereda first region, is provided on the lower substrate 101, and memory cellregions CELL, which may be considered a second region, may be providedon the upper substrates 201. The semiconductor device 10 may includecutting regions 265 spaced apart from each other on a periphery of theupper substrates 201. The cutting regions 265 may be disposed betweenthe upper substrates 201. As illustrated, two or three cutting regions265 are arranged between the upper substrates 201, but exampleembodiments are not limited thereto. The semiconductor device 10 mayinclude semiconductor patterns 210 disposed between the upper substrates201 and the cutting regions 265 and protruding from the upper substrates201 in a horizontal direction (e.g., X-direction and/or Y-direction).The semiconductor patterns 210 may be in contact with the cuttingregions 265, respectively. The semiconductor patterns 210 may be bridgepatterns.

The peripheral circuit region PERI may include a lower substrate 101,circuit elements 120 disposed on the lower substrate 101, a lowerinterlayer insulating layer 150 covering the circuit elements 120, and alower wiring structure 130.

The lower substrate 101 may have an upper surface extended in anX-direction and a Y-direction. The lower substrate 101 may include asemiconductor material, such as a Group IV semiconductor, a Group III-Vcompound semiconductor, and/or a Group II-VI compound semiconductor. Forexample, the Group IV semiconductor may include silicon, germanium,and/or silicon-germanium. The lower substrate 101 may be provided as abulk wafer or an epitaxial layer. The lower substrate 101 may includewell regions including an impurity and element isolation regions 105.

The circuit elements 120 may include a circuit gate dielectric layer121, a circuit gate electrode layer 123, and a source/drain region 125.The circuit gate dielectric layer 121 may include silicon oxide, whilethe circuit gate electrode layer 123 may include a conductive material,such as a metal, polycrystalline silicon, and/or metal silicide. Thesource/drain region 125 may be doped with an impurity. In someembodiments, a spacer may be disposed on each of the sidewalls of thecircuit gate electrode layer 123. For example, the spacer may be formedof silicon nitride.

The lower interlayer insulating layer 150 may cover or overlap at leasta portion of the lower substrate 101 and the circuit elements 120 on thelower substrate 101, and may be disposed between the lower substrate 101and the upper substrate 201. The lower interlayer insulating layer 150may be formed of an insulating material.

The lower wiring structure 130 may include a first lower contact plug131, a first lower wiring line 133, a second lower contact plug 135, anda second lower wiring line 137, sequentially stacked from thesource/drain region 125 of the lower substrate 101. The number of wiringlines, forming the lower wiring structure 130, may be varied in variousexample embodiments. The lower wiring structure 130 may include a metal,for example, one or more of tungsten (W), copper (Cu), aluminum (Al), orthe like.

The memory cell region CELL may include upper substrates 201, gateelectrodes 230 spaced apart from each other and stacked perpendicularlyto an upper surface of the upper substrates 201, mold insulating layers220 alternately stacked with the gate electrodes 230, channel structuresCHS disposed to pass through the gate electrodes 230, first to thirdupper interlayer insulating layers 250, 252, and 254, at least partiallycovering the gate electrodes 230 and gate contact plugs 281. A groundselect transistor, memory cells, and a string select transistor arevertically arranged along each of the channel structures CHS, therebyforming a single memory cell string.

The upper substrates 201 may each have an upper surface extended in anX-direction and a Y-direction. The upper substrates 201 may each bedisposed to have a size smaller than that of the lower substrate 101.The upper substrates 201 may include a semiconductor material, such as aGroup IV semiconductor. For example, the upper substrates 201 may beprovided as a polycrystalline silicon layer, but example embodiments arenot limited thereto. For example, the upper substrates 201 may beprovided as an epitaxial layer. The upper substrates 201 may include atleast one well region including an impurity. For example, the entiretyof an upper substrate 201 may form a single p-well region.

The gate electrodes 230 are spaced apart from each other and stackedperpendicularly to the upper substrates 201, and may be extended todifferent lengths in at least one direction, for example, in anX-direction. Each of the gate electrodes 230 may form a ground selectionline of ground selection transistors of the semiconductor device 10, aword line of memory cells, and a string selection line of stringselection transistors. The number of the gate electrodes 230 may bevariously changed based on the data storage capacity of thesemiconductor device 10. The gate electrodes 230 may include a metalmaterial, such as tungsten (W). According to an example embodiment, thegate electrodes 230 may include polycrystalline silicon and/or a metalsilicide material. In example embodiments, the gate electrodes 230 mayfurther include a diffusion barrier. For example, the diffusion barriermay include tungsten nitride (WN), tantalum nitride (TaN), titaniumnitride (TiN), or a combination thereof.

The mold insulating layers 220 may be disposed between the gateelectrodes 230. The mold insulating layers 220 are spaced apart fromeach other in a direction, perpendicular to an upper surface of theupper substrate 201, and may be disposed to be extended to differentlengths in an X-direction in a manner similar to the gate electrodes230. The mold insulating layers 220 may include an insulating material,such as silicon oxide or silicon nitride.

The channel structures CHS may be spaced apart from each other and maybe arranged in rows and columns on the upper substrate 201. The channelstructures CHS may be disposed to form a lattice pattern on an X-Y planeor may be arranged in a zigzag form in one direction. The channelstructures CHS may have a columnar shape and may have an inclined sidesurface. The channel structures CHS may have a diameter or width, whichnarrows toward the upper substrate 201.

Each of the channel structures CHS may include an epitaxial layer 261, agate dielectric layer 263, a channel region 264, a channel insulatinglayer 267, and a channel pad 269. In the channel structures CHS, thechannel region 264 may have an annular shape surrounding the channelinsulating layer 267, formed therein. However, the channel region 264may have a columnar shape without the channel insulating layer 267, suchas a cylinder or a prism, according to an example embodiment. Thechannel region 264 may be electrically connected to the epitaxial layer261, disposed therebelow. The epitaxial layer 261 may be disposed on theupper substrate 201 at a lower end of the channel structures CHS. Theepitaxial layer 261 may be disposed in a recessed region of the uppersubstrate 201. A level of an upper surface of the epitaxial layer 261may be higher than a lever of an upper surface of a lowermost gateelectrode 230 and may be lower than a level of a lower surface of a gateelectrode 230, directly above the lowermost gate electrode, relative tothe lower substrate 101. In example embodiments, the epitaxial layer 261may be omitted. In this case, the channel region 264 may be directlyconnected to the upper substrate 201. The channel pads 269 may bedisposed to cover or overlap an upper surface of the channel insulatinglayer 267 and to be electrically connected to the channel region 264.The epitaxial layer 261 and the channel region 264 may include asemiconductor material such as polycrystalline silicon or single crystalsilicon, and the semiconductor material may be an undoped material, or amaterial doped with a p-type or n-type impurity. The channel pads 269may include, for example, doped polycrystalline silicon. The gatedielectric layer 263 may be disposed between the gate electrodes 230 andthe channel region 264. The gate dielectric layer 263 may have anannular shape surrounding the channel region 264. The gate dielectriclayer 263 may include a tunneling layer, a charge storage layer, and ablocking layer, sequentially stacked from the channel region 264. Thetunneling layer may allow a charge to tunnel to the charge storagelayer, and may include, for example, silicon oxide (SiO₂), siliconnitride (Si₃N₄), silicon oxynitride (SiON), or a combination thereof.The charge storage layer may be a charge trap layer or a floating gateconductive layer. The blocking layer may include silicon oxide (SiO₂),silicon nitride (Si₃N₄), silicon oxynitride (SiON), a high-k dielectricmaterial, or a combination thereof. In example embodiments, at least aportion of the gate dielectric layer 263 may be extended in a horizontaldirection along the gate electrodes 230.

The first upper interlayer insulating layer 250 may be disposed to coveror overlap at least a portion of the upper substrate 201, thesemiconductor pattern 210, and the gate electrodes 230 provided on theupper substrate 201. The second upper interlayer insulating layer 252and the third upper interlayer insulating layer 254 may be stacked onthe first upper interlayer insulating layer 250. The first upperinterlayer insulating layer 250, the second upper interlayer insulatinglayer 252, and the third upper interlayer insulating layer 254 may beformed of an insulating material.

The semiconductor device 10 may further include a through region 260disposed to pass through the upper substrate 201 and a cutting region265 between the semiconductor patterns 210 so as to cut or separate thesemiconductor patterns 210 from each other. The through region 260 maypass through the gate electrodes 230, the mold insulating layers 220,and the upper substrate 201 so as to be extended to an upper portion ofthe lower interlayer insulating layer 150. The through region 260 may bea region in which a first through plug 285 for connection of the memorycell region CELL and the peripheral circuit region PERI is provided. Thethrough region 260 may be disposed between a region in which the channelstructures CHS are provided and a region in which the gate contact plugs281 are provided. The through region 260 may include an insulatingmaterial, and a first through plug 285 may be disposed therein. Thefirst through plug 285 may be electrically connected to the circuitelements 120 through the lower wiring structure 130. The first throughplug 285 may be connected to a gate contact plug 281, a channelstructure CHS, and the like through an upper wiring structure (notshown). A sidewall of the through region 260 may have a shape, which isinclined and of which a width narrows downwardly. For example, a lowersurface of the through region 260 may be narrower than an upper surfacethereof, and an upper width of the through region 260 may be greaterthan a lower width thereof. The second through plugs 287 may be formedbetween the cutting regions 265 and may be electrically connected to thecircuit elements 120 while passing through the first upper interlayerinsulating layer 250.

The cutting region 265 may pass through the first upper interlayerinsulating layer 250, the second upper interlayer insulating layer 252,and the third upper interlayer insulating layer 254, as well as thesemiconductor pattern 210 so as to be extended to an upper portion ofthe lower interlayer insulating layer 150.

The cutting region 265 may be located between the upper substrates 201.The cutting region 265 may include an insulating material.

A lower surface of the through region 260 and a lower surface of thecutting region 265 may be located lower than a lower surface of theupper substrate 201 relative to the lower substrate 101. The throughregion 260 and the cutting region 265 may be formed using differentetching processes, and levels of lower surfaces thereof may be differentfrom each other.

A height of the cutting region 265 may be greater than a height of thethrough region 260. An upper surface of the cutting region 265 may belocated higher than an upper surface of the through region 260 relativeto the lower substrate 101.

A sidewall of the cutting region 265 may have a shape, which is inclinedand of which a width narrows downwardly toward the lower substrate 101.For example, a lower surface of the cutting region 265 may be narrowerthan an upper surface thereof, and an upper width of the cutting region265 may be wider than a lower width thereof. Moreover, a height of thecutting region 265 may be greater than a height of the channelstructures CHS. An upper surface of the cutting region 265 may belocated higher than an upper surface of the channel structure CHSrelative to the lower substrate 101. However, a shape of the cuttingregion 265 and a relative size of the cutting region 265 and the throughregion 260 are not limited to those illustrated in the drawings, and maybe variously changed in example embodiments.

The semiconductor device 10 may further include separation regions SRdividing and intersecting the gate electrodes 230 of the memory cellregions CELL in an X-direction. The separation region SR includes aninsulating layer 273 and a conductive layer 275, and the conductivelayer 275 is a common source line for driving memory cells. Impurityregions 271 may be disposed below the separation regions SR,respectively, in the upper substrate 201.

A portion of the separation regions SR may include a portion divided toat least partially surround the through regions 260.

FIG. 4 is a schematic plan view illustrating a portion of asemiconductor device according to an example embodiment of the inventiveconcept, and illustrates a region corresponding to FIG. 2 . FIG. 5 is aschematic cross-sectional view of a semiconductor device according to anexample embodiment of the inventive concept, and a cross-sectional viewtaken along line I-I′ of FIG. 4 .

Referring to FIGS. 4 and 5 , in a semiconductor device 10A in theexample embodiment, a semiconductor pattern 210 a may have a concavegroove in contact with the cutting region 265 a, in a manner differentfrom the semiconductor device 10 of FIGS. 1 to 3 . The cutting region265 a may include a contact portion (a protruding portion) in contactwith the concave groove of the semiconductor pattern 210 a, and thecontact portion (the protruding portion) may include a convex curvedsurface.

The cutting region 265 a may be provided by forming an opening passingthrough the first upper interlayer insulating layer 250, the secondupper interlayer insulating layer 252, and the third upper interlayerinsulating layer 254, as well as the semiconductor pattern 210 a usingan anisotropic dry etching process, and then removing a portion of thesemiconductor pattern 210 a using an additional wet etching process, aswill be described with reference to FIG. 26 . The wet etching processmay be performed by an etching solution configured to etch, for example,polycrystalline silicon.

FIG. 6 is a schematic plan view of a semiconductor device according toan example embodiment of the inventive concept. FIG. 7 is an enlargedview of region ‘A’ of FIG. 6 . FIG. 8 is a schematic cross-sectionalview of a semiconductor device according to an example embodiment of theinventive concept, and a cross-sectional view taken along line I-I′ ofFIG. 7 .

Referring to FIGS. 6, 7 and 8 , a semiconductor device 10B according tothe example embodiment may include semiconductor patterns 210′ disposedbetween upper substrates 201 and spaced apart from the upper substrates201. Cutting regions 265′ may be disposed between the upper substrates201 and the semiconductor patterns 210′. Each of the cutting regions265′ may be in contact with the upper substrate 201 and thesemiconductor patterns 210′. The upper substrate 201 and thesemiconductor pattern 210′ may be electrically insulated by the cuttingregion 265′. As a result, the upper substrates 201 may be electricallyinsulated by the cutting region 265′.

FIG. 9 is a schematic plan view illustrating a portion of asemiconductor device according to an example embodiment of the inventiveconcept, and illustrates a region corresponding to FIG. 7 . FIG. 10 is aschematic cross-sectional view of a semiconductor device according to anexample embodiment of the inventive concept, and a cross-sectional viewtaken along line I-I′ of FIG. 9 .

Referring to FIGS. 9 and 10 , in a manner different from thesemiconductor device 10B of FIGS. 6 to 8 , in a semiconductor device 10Caccording to the example embodiment, a semiconductor pattern 210 a′ mayhave concave first grooves in contact with cutting regions 265 a′. Anupper substrate 201 may also have concave second grooves in contact withthe cutting regions 265 a′. The cutting region 265 a may include contactportions (protruding portions) in contact with the first groove of thesemiconductor pattern 210 a′ and the second groove of the uppersubstrate 201, and the contact portions (the protruding portions) mayinclude a convex curved surface.

FIGS. 11 to 14 are schematic plan views illustrating a portion of asemiconductor device according to example embodiments of the inventiveconcept.

Referring to FIG. 11 , in a manner different from the semiconductordevice 10 of FIGS. 1 to 3 , a semiconductor device 10D according to theexample embodiment may include a single cutting region 265 b betweenneighboring upper substrates 201. Three semiconductor patterns 210,protruding from the upper substrate 201, may be in contact with a singlecutting region 265 b.

Referring to FIG. 12 , in a manner different from the semiconductordevice 10 of FIGS. 1 to 3 , a semiconductor device 10E according to theexample embodiment may include a cutting region 265 c at least partiallysurrounding upper substrates 201. The cutting region 265 c may be incontact with all the semiconductor patterns 210 protruding from theupper substrates 201.

Referring to FIG. 13 , in a manner different from the semiconductordevice 10B of FIGS. 6 to 7 , in a semiconductor device 10F according tothe example embodiment, three semiconductor patterns 210′, disposedbetween neighboring upper substrates 201, may be in contact with asingle cutting region 265 b′.

A single cutting region 265 b′ between the upper substrate 201 and threesemiconductor patterns 210′ may be disposed on a side surface of theupper substrate 201. The cutting region 265 b′ may be disposed on eachof four side surfaces of the upper substrate 201.

Referring to FIG. 14 , in a manner different from the semiconductordevice 10B of FIGS. 6 to 7 , a semiconductor device 10G according to theexample embodiment may include cutting regions 265 c′ at least partiallysurrounding upper substrates 201, respectively. The cutting region 265c′ may be in contact with some or all side surfaces of the uppersubstrate 201, and may be in contact with the semiconductor patterns210′.

FIG. 15 is a schematic plan view illustrating a portion of asemiconductor device according to an example embodiment of the inventiveconcept. FIG. 16 is a schematic cross-sectional view of a semiconductordevice according to an example embodiment of the inventive concept, anda cross-sectional view taken along line I-I′ of FIG. 15 .

Referring to FIGS. 15 and 16 , a semiconductor device 10H according tothe example embodiment may include cutting regions 265 d, disposedbetween neighboring upper substrates 201, and in contact with the uppersubstrates 201. In the semiconductor device 10H according to the exampleembodiment, semiconductor patterns are not present between the uppersubstrates 201.

FIGS. 17 to 26 are schematic cross-sectional views illustrating a methodfor manufacturing a semiconductor device according to exampleembodiments of the inventive concept. In FIGS. 17, 19 to 21, and 23 to26 , regions corresponding to the region illustrated in FIG. 3 areillustrated therein. In FIGS. 18 and 22 , an edge region of a lowersubstrate 101 is illustrated therein.

Referring to FIGS. 17 and 18 , circuit elements 120 and lower wiringstructures 130 may be provided on the lower substrate 101. An elementisolation region 105 may be provided between the circuit elements 120.

First, a circuit gate dielectric layer 121 and a circuit gate electrodelayer 123 may be formed on the lower substrate 101. The circuit gatedielectric layer 121 may be formed of silicon oxide, and the circuitgate electrode layer 123 may be formed of polycrystalline silicon, metalsilicide, and/or metal, but example embodiments are not limited thereto.Then, source/drain regions 125 may be formed in upper portions of thelower substrate 101 at both sides of the circuit gate electrode layer123.

Lower wiring structures 130 and a lower interlayer insulating layer 150may be formed on the lower substrate 101. The lower wiring structures130 may include a first lower contact plug 131, a first lower wiringline 133, a second lower contact plug 135, and a second lower wiringline 137. The lower interlayer insulating layer 150 may be formed of aplurality of insulating layers.

Moreover, on the lower interlayer insulating layer 150, an uppersubstrate 201 and a semiconductor pattern 210 extended from the uppersubstrate 201 may be provided thereon. FIG. 18 illustrates an edgeregion of the lower substrate 101. In the edge region of the lowersubstrate 101, the semiconductor pattern 210 is extended along a sidesurface of the lower interlayer insulating layer 150, and may be incontact with the lower substrate 101.

The upper substrate 201 and the semiconductor pattern 210 may be formedof, for example, polycrystalline silicon. The upper substrate 201 mayinclude, for example, a p-type impurity. The upper substrate 201 may bedisposed to have a size smaller than that of the lower substrate 101.

Referring to FIG. 19 , on the upper substrate 201, sacrificial layers240 and mold insulating layers 220 are alternately stacked, and portionsof the sacrificial layers 240 and the mold insulating layers 220 may beremoved to be extended at different lengths in an X-direction, byrepeatedly performing a photolithography process and etching process.Thus, the sacrificial layers 240 and the mold insulating layers 220 mayhave a stepped form.

The sacrificial layers 240 may be layers to be replaced with the gateelectrodes 230 through a subsequent process. The sacrificial layers 240may be formed of a material to be etched while having etch selectivityto the mold insulating layers 220. For example, the mold insulatinglayer 220 may be formed of silicon oxide and/or silicon nitride, and thesacrificial layers 240 may be formed of a material, different from themold insulating layer 220, and may comprise silicon, silicon oxide,silicon carbide, and/or silicon nitride. A portion of the moldinsulating layers 220 may have a thickness different from that of theremaining portion.

Next, a stacked structure of the sacrificial layers 240 and the moldinsulating layers 220, and a first upper interlayer insulating layer 250at least partially covering the upper substrate 201 and thesemiconductor pattern 210, may be provided.

Referring to FIG. 20 , a through region 260, passing through the stackedstructure of sacrificial layers 240 and mold insulating layers 220, andan upper substrate 201 may be provided.

An opening passing through the stacked structure of the sacrificiallayers 240 and the mold insulating layers 220, and the upper substrate201 to expose a lower interlayer insulating layer 150 is formed, and theopening is filled with an insulating material to form a through region260. An upper surface of the through region 260 may be coplanar with anupper surface of an uppermost sacrificial layer 240.

Referring to FIGS. 21 and 22 , channel holes CHH, passing through astacked structure of sacrificial layers 240 and mold insulating layers220, may be provided.

A mask layer 270, including hard mask layers, an amorphous carbon layer(ACL), and the like are provided on the mold insulating layers 220, thethrough region 260, and the first upper interlayer insulating layer 250to form the channel holes CHH. Referring to FIG. 22 , in an edge regionof the lower substrate 101, the semiconductor pattern 210 may beextended along a side surface of the lower interlayer insulating layer150 to be in contact with the lower substrate 101. Moreover, the masklayer 270 may be extended along a side surface of the first upperinterlayer insulating layer 250 to be in contact with the lowersubstrate 101.

The channel holes CHH may have a form of a hole having a high aspectratio, and may be formed using an anisotropic etching process. Due to aheight of the stacked structure, that is, due to a high aspect ratio, asidewall of the channel holes CHH may not be perpendicular to an uppersurface of the upper substrate 201. In example embodiments, the channelholes CHH may be formed to allow a portion of the upper substrate 201 tobe recessed.

When a plasma dry etching process is used during formation of thechannel holes CHH, a potential difference between an upper portion and alower portion of the channel holes CHH may occur by positive ions andelectrons. However, in example embodiments, the upper substrate 201 isconnected to the lower substrate 101 by the semiconductor pattern 210 toallow the positive ions to flow to the lower substrate 101, and theelectrons may flow to the lower substrate 101 through the mask layer270, thereby preventing or reducing the likelihood of an arcing defectcaused by the potential difference.

Referring to FIG. 23 , an epitaxial layer 261, a gate dielectric layer263, a channel region 264, a channel insulating layer 267, and a channelpad 269 are formed in the channel holes CHH, to form channel structuresCHS.

The epitaxial layer 261 may be formed using a selective epitaxial growth(SEG) process. The epitaxial layer 261 may be formed of a single layeror a plurality of layers. The epitaxial layer 261 may includepolycrystalline silicon, monocrystalline silicon, polycrystallinegermanium, and/or monocrystalline germanium, doped with an impurity orundoped. The gate dielectric layer 263 may be formed to have a uniformthickness using ALD or CVD. The channel region 264 may be provided onthe gate dielectric layer 245 in the channel holes CHH, and a lowerportion of the channel region 264 may pass through the gate dielectriclayer 245 to be connected to the epitaxial layer 261. The channelinsulating layer 267 may be formed to fill an internal space of thechannel region 264, and may be an insulating material. However,according to example embodiments, rather than the channel insulatinglayer 267, a conductive material may fill the internal space of thechannel regions 264. The channel pad 269 may be formed of a conductivematerial, for example, polycrystalline silicon.

Referring to FIG. 24 , an opening OP is provided, and sacrificial layers240 may be removed using the opening. Moreover, a conductive material isembedded in a region from which the sacrificial layers 240 are removedto form the gate electrodes 230.

The gate electrodes 230 may include metal, polycrystalline silicon,and/or a metal silicide material. In example embodiments, before thegate electrodes 230 are provided, a portion of the gate dielectric layer263 may be provided first.

Before the opening OP is provided, a second upper interlayer insulatinglayer 252, covering the mold insulating layer 220, the channelstructures CHS, the through region 260, and the first upper interlayerinsulating layer 250, may be provided.

The sacrificial layers 240, exposed through the opening OP, may beselectively removed using, for example, wet etching.

Referring to FIG. 25 , an impurity is injected into the upper substrate201, exposed by the opening OP, to form an impurity region 271. Then, aninsulating layer 273 and a conductive layer 275 are formed in theopening OP. The insulating layer 273 and the conductive layer 275 may bea separation region SR. The conductive layer 275 may be a common sourceline. The conductive layer 275 may include, for example, tungsten,copper, and/or aluminum.

Referring to FIG. 26 , a cutting region 265, passing through the firstupper interlayer insulating layer 250, the second upper interlayerinsulating layer 252, and the third upper interlayer insulating layer254, as well as the semiconductor pattern 210, may be provided.

A third upper interlayer insulating layer 254, covering the second upperinterlayer insulating layer 252, may be provided. Then, an openingpassing through the first upper interlayer insulating layer 250, thesecond upper interlayer insulating layer 252, and the third upperinterlayer insulating layer 254, as well as the semiconductor pattern210, to expose the lower interlayer insulating layer 150 is providedusing an anisotropic dry etching process, and the opening is filled withan insulating material to form a cutting region 265. An upper surface ofthe cutting region 265 may be coplanar with an upper surface of a secondupper interlayer insulating layer 252. An upper surface of the cuttingregion 265 may be located higher than an upper surface of the throughregion 260 relative to the lower substrate 101. An upper surface of thecutting region 265 may be located higher than an upper surface of thechannel structure CHS relative to the lower substrate 101. In otherwords, an upper surface of the cutting region 265 may be located higherthan an upper surface of the channel pad 269 relative to the lowersubstrate 101.

The insulating material may be provided using a CVD or physical vapordeposition (PVD) process.

The cutting regions 265, between so as to cut or separate thesemiconductor patterns 210 connecting the upper substrates 201 to eachother, and connecting the upper substrate 201 to the lower substrate101, is provided, thereby allowing the upper substrates 201 to be in afloating state.

Referring again to FIGS. 2 and 3 , gate contact plugs 281 passingthrough the first upper interlayer insulating layer 250 and connected tothe gate electrodes 230, and a first through plug 285 passing throughthe through region 260 and connected to the lower wiring structure 130,may be provided. Together with the first through plug 285, a secondthrough plug 287 may be provided between the cutting regions 265.

As set forth above, according to example embodiments of the presentinventive concept, after a process of etching channel holes, a cuttingregion cutting a bridge pattern connecting upper substrates is formed,thereby providing a semiconductor device with improved reliability and amethod for manufacturing the same.

While example embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentdisclosure, as defined by the appended claims.

What is claimed is:
 1. A semiconductor device, comprising: a peripheralcircuit region including a lower substrate and circuit elements on thelower substrate; a first upper substrate and a second upper substrate onthe peripheral circuit region; a first memory cell region on the firstupper substrate and a second memory cell region on the second uppersubstrate; and at least one cutting region between the first uppersubstrate and the second upper substrate, the at least one cuttingregion formed of an insulating material; wherein each of the first andsecond memory cell region comprises: a plurality of gate electrodesstacked in a vertical direction perpendicular to an upper surface of thelower substrate and spaced apart from each other; a plurality ofseparation regions penetrating through the plurality of gate electrodesin the vertical direction and extending in a first direction parallel toan upper surface of the lower substrate; and a plurality of channelstructures penetrating through the plurality of gate electrodes andextending in the vertical direction, each of the plurality of channelstructures including a channel layer, wherein the at least one cuttingregion is disposed between first step-shaped end portions of theplurality of gate electrodes of the first memory cell region and secondstep-shaped end portions of the plurality of gate electrodes of thesecond memory cell region, wherein a height of the at least one cuttingregion in the vertical direction is greater than at least one of aheight of one of the plurality of channel structures in the verticaldirection and a height of one of the plurality of separation regions inthe vertical direction, and wherein a bottom of the at least one cuttingregion is located lower than a bottom of each of the first uppersubstrate and the second upper substrate.
 2. The semiconductor device asclaimed in claim 1, wherein a top of the at least one cutting region islocated higher than a top of the one of the plurality of channelstructures relative to the upper surface of the lower substrate.
 3. Thesemiconductor device as claimed in claim 1, wherein a top of the atleast one cutting region is located higher than a top of the one of theplurality of separation regions relative to the upper surface of thelower substrate.
 4. The semiconductor device as claimed in claim 1,wherein each of the plurality of channel structures further includes acore insulating layer which side surfaces are surrounded by the channellayer and a gate dielectric layer between the channel layer and theplurality of gate electrodes.
 5. The semiconductor device as claimed inclaim 4, wherein each of the plurality of channel structures furtherincludes a channel pad disposed on the core insulating layer and incontact with the channel layer, and wherein a top of the at least onecutting region is located higher than a top of the channel pad relativeto the upper surface of the lower substrate.
 6. The semiconductor deviceas claimed in claim 1, further comprising at least one semiconductorpattern between the first upper substrate and the second upper substrateand in contact with the at least one cutting region.
 7. Thesemiconductor device as claimed in claim 6, wherein the at least onesemiconductor pattern is between the at least one cutting region and thefirst upper substrate and protrudes from the first upper substrate in ahorizontal direction in a plan view of the semiconductor device.
 8. Thesemiconductor device as claimed in claim 7, wherein the at least onecutting region includes a protruding portion in contact with the atleast one semiconductor pattern, the protruding portion having a convexcurved surface.
 9. The semiconductor device as claimed in claim 6,wherein the at least one semiconductor pattern is spaced apart from thefirst upper substrate and the second upper substrate, and wherein the atleast one cutting region includes a first cutting region between thefirst upper substrate and the at least one semiconductor pattern and asecond cutting region between the second upper substrate and the atleast one semiconductor pattern.
 10. The semiconductor device as claimedin claim 9, wherein each of the first cutting region and the secondcutting region includes a protruding portion in contact with the atleast one semiconductor pattern, the protruding portion having a convexcurved surface.
 11. The semiconductor device as claimed in claim 1,wherein the first upper substrate and the second upper substrate arespaced apart from each other.
 12. A semiconductor device, comprising: aperipheral circuit region including a lower substrate and circuitelements on the lower substrate; a first upper substrate and a secondupper substrate on the peripheral circuit region; a first memory cellregion on the first upper substrate and a second memory cell region onthe second upper substrate; and at least one cutting region between thefirst upper substrate and the second upper substrate, the at least onecutting region formed of an insulating material; wherein the first uppersubstrate includes a first protruding portion extending from the firstupper substrate towards the second upper substrate, and the second uppersubstrate includes a second protruding portion extending from the secondupper substrate towards the first upper substrate, wherein the at leastone cutting region is in contact with a first side surface of the firstprotruding portion and a second side surface of the second protrudingportion, wherein each of the first and second memory cell regioncomprises: a plurality of gate electrodes stacked in a verticaldirection perpendicular to an upper surface of the lower substrate andspaced apart from each other; and a plurality of channel structurespenetrating through the plurality of gate electrodes and extending inthe vertical direction, each of the plurality of channel structuresincluding a channel layer, and wherein a height of the at least onecutting region in the vertical direction is greater than a height of oneof the plurality of channel structures in the vertical direction. 13.The semiconductor device as claimed in claim 12, wherein a top of the atleast one cutting region is located higher than a top of the one of theplurality of channel structures relative to the upper surface of thelower substrate, and wherein a bottom of the at least one cutting regionis located lower than a bottom of the one of the plurality of channelstructures relative to the upper surface of the lower substrate.
 14. Thesemiconductor device as claimed in claim 13, wherein the bottom of theat least one cutting region is located lower than a bottom of each ofthe first upper substrate and the second upper substrate.
 15. Thesemiconductor device as claimed in claim 12, wherein the first sidesurface of the first protruding portion has a concave portion and thesecond side surface of the second protruding portion has a concaveportion.
 16. The semiconductor device as claimed in claim 15, wherein aside surface of the at least one cutting region includes a convexportion in contact with the first side surface of the first protrudingportion and the second side surface of the second protruding portion.17. A semiconductor device, comprising: a lower substrate; circuitelements on the lower substrate; a lower interlayer insulating layer atleast partially covering the circuit elements on the lower substrate; aplurality of upper substrates on the lower substrate; a plurality ofstack structures on the plurality of upper substrates, respectively,each of the plurality of stack structures including mold insulatinglayers and gate electrodes alternately stacked; a plurality of channelstructures penetrating through the plurality of stack structures andextending in a vertical direction perpendicular to an upper surface ofthe lower substrate; an upper interlayer insulating layer at leastpartially covering the plurality of stack structures; and at least onecutting region between the plurality of upper substrates, the at leastone cutting region formed of an insulating material, wherein the atleast one cutting region penetrating through the upper interlayerinsulating layer and spaced apart from the plurality of stack structuresin a horizontal direction in a plan view of the semiconductor device,and wherein a height of the at least one cutting region in the verticaldirection is greater than a height of one of the plurality of channelstructures in the vertical direction.
 18. The semiconductor device ofclaim 17, further comprising a plurality of semiconductor patternsbetween the at least one cutting region and the plurality of uppersubstrates, and protruding from the plurality of upper substrates in ahorizontal direction in a plan view of the semiconductor device.
 19. Thesemiconductor device as claimed in claim 18, wherein the at least onecutting region comprises a plurality of cutting regions spaced apartfrom each other, and wherein the plurality of cutting regions are incontact with the plurality of semiconductor patterns, respectively. 20.The semiconductor device as claimed in claim 17, further comprising aplurality of semiconductor patterns between the plurality of uppersubstrates, wherein the at least one cutting region comprises aplurality of cutting regions between the plurality of semiconductorpatterns and the plurality of upper substrates, and wherein theplurality of cutting regions are extended along a side surface of theplurality of upper substrates in contact with one of the plurality ofupper substrates and in contact with the plurality of semiconductorpatterns.